DE3116235A1 - WORKSHOP MEASURING DEVICE FOR CHECKING THE DIMENSIONING ACCURACY OF LARGE OBJECTS - Google Patents

Description

PATENT Attorney DIPL.-ING. H. STRAW BAR

8000 MUNICH 60 · MUSÄUSSTRASSE 5 ■ TELEPHONE (0 89) 881608

April 23, 1981-SvSe (S) 190J-1603P

jSchwederO

Workshop measuring device for checking the dimensional accuracy - -

large objects.

The invention relates to a workshop measuring device according to. the genus of claim 1.

The vehicle bodies of today's motor vehicles are made in large groups and self-supporting with great precision in a shell construction manufactured. The drive motor and the drive transmission are provided as a front and rear assembly by means of stiffeners and brackets welded to the vehicle body are fixed more or less directly to the vehicle body. Consequently is the correct function of the motor vehicle to a large extent dependent on the attachment points, for example for the steering units of the front and rear assemblies, always exactly those. Take the positions provided by the manufacturer.

In the event of an accident, the impact forces often affect the vehicle body into it and thus leave permanent deformations. Without a complete check and measurement '.! es It is then difficult for the vehicle body to return deformed parts to their original position, and if this is not the case if successful, this can have detrimental consequences for the steering characteristics of the vehicle, for example. Minor deformations in the chassis can- through those provided in the front structure

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Adjustment options are compensated; on the other hand it is by no means permissible, the suspension points of the front subassembly, for example, by enlarging the mounting holes for retaining screws and the like "to align".

In the genre of claim 1 corresponding DE-PS 22 13 963 a workshop measuring device is disclosed with the it can be checked whether a motor vehicle - for example after an accident - is correct for the respective model Has retained dimensions. For this purpose, the vehicle is lifted into a clamping device or a straightening bench.

The ones used to check the dimensions of a chassis Control points of a vehicle consist of recesses located on the underside of holding devices as well Locating holes for screws and screw connections. So that these control points can be precisely defined, used one sucked Measuring point units that are attached to all required control points on the vehicle chassis. At each measuring point unit . becomes a ruler with a millimeter scale hung, along d, em a slide to a desired height level can be preset. By reading the from one Light beam struck point of these rulers can cause any deviations in height of the chassis from the constructively intended Can be read off immediately. By means of reflective colored markings can indicate the position of a light beam on "the Rulers easily even over a distance of several meters

to be established. The from. light emanating from a light source beam hits a deflection unit, where it is branched into two mutually perpendicular beams. The one ray of light closes in the direction of the incoming light beam along the measuring beam, while the other is perpendicular to the measuring beam connects. When the movable along the measuring beam The deflection unit is shifted, so that the light beam emanating from the same right-angled until it reaches both

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for example hits a ruler. With two along that Measuring bar displaceable deflection units can for example se the distance between two rulers immediately .an am Arranged measuring bars and read along the same rollable tape measure.

In this way, all the longitudinal and transverse dimensions of one Vehicle chassis are measured. To measure a transverse dimension, a deflection unit is placed on the along the The measuring beam extending from the vehicle to that of the light source shifted remote outer end, so that the deflected by this deflection unit now along the transverse to Vehicle running measuring beam connects and over along

. this measuring beam displaceable further deflection units in the same In the same way as for the measurement from the other measuring beam.

15. is used.

When a vehicle body needs to be realigned after an accident, for example, the operator provides the deflection units on the corresponding measuring bar one after the other on those layers that they correspond to the for This model must take correct data so that the light beam with a perfect shape of the vehicle body hits the assigned rulers. Meets with any If the light beam then does not correctly point to the assigned ruler, the vehicle body has to be aligned for that long until this ruler is properly hit by the light beam.

Since in the aforementioned known measuring device to each ruler If only a deflected light beam hits a measurement, several readjustments may then be necessary in particular when aligning a vehicle body for one and the same measuring point an alignment not only in the one direction X, in which the light beam passes through a measuring beam extending in the longitudinal direction of the vehicle Deflection unit is deflected towards the measuring point,

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but at the same time must take place in the other direction Y, at

■ that the light beam through one, on the one running across the vehicle Measuring bar located deflection unit is deflected to the same measuring point. There must be one in the direction

'5 Y made alignment, the alignment previously carried out in the X direction is not only checked, but under certain circumstances must be done again, which can take a lot of time and effort. ·.

The invention is based on the object of perfecting the measuring device corresponding to the preamble of claim 1 so that that for each measuring point the alignment in both directions X and Y is carried out at the same time, if possible can be checked.

The posed task is according to the invention, starting from 1 ⁷ S eier genus of claim 1 by the characterizing

■ features reproduced in the drawing part.

With one such design of the measuring device, two Light beams according to the target data for the affected object according to the same. Be radiated towards the measuring point must be in the correct position of the assigned ruler when the body is correctly aligned. Since it can be difficult with two on the same point - for example a ruler - To check directed beams that both points of impact actually coincide exactly with the measuring point, it is 5 particularly advantageous that the light beams emitted by the two deflection units • according to the invention in each case with a frequency perceived as flickering by the human eye and the modulations of the light beams emanating from both deflection units are out of phase with one another. The light intervalI each include a phase angle of 180 ° and the modulation frequency 'can also be selected in such a way that the

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mern of the an dex common point of impact with double i-Iodv --- ■ lation frequency of reflected light from the eye as a constant irrigation Light is felt. In both cases the eye can be very clear distinguish whether the light rays emanating from the deflection units do not hit exactly one and the same point, because the point of light observed at the point of impact then. flickers. Only if both light rays are on exactly one and the same Point are aligned, the dorticje point of light appears as constant light.

When aligning a vehicle body series, According to the data valid for the vehicle model, light beams are set to one and the same measuring point and the diamonds series is aligned until the operator performing the alignment on the

T5 gives the associated ruler a non-flickering permanent one Point of light sees.

Further embodiments of the invention are in the .Un t ^ ran claims marked.

In the drawing, the invention is illustrated by way of example; show it:

Fig. 1 shows a first embodiment of the measuring device in connection with an object to be measured in a perspective side view;

Fig. 2 shows a second embodiment of the measuring device in a similar perspective side view;

3 shows a schematic representation of a first embodiment means of the meter for modulating the light;

Fig. 4 shows a second embodiment of a device for Modulating the light in a same schematic;

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Fig. 5 shows a third embodiment of a device for Modulating the light in the same schematic representation.

• The first embodiment of the measuring device shown in FIG. 5 rätes is used to measure and accurately display the correct dimensions of a vehicle. The illustrated motor vehicle 1 is suspended from a lifting device (not shown) and. hang from measuring points located on its underside attached rulers 2 to 7. The measuring points and measurements go for a standard vehicle of each vehicle model from special measurement documents.

Flat below the suspended vehicle are two transverse measuring beams 8 and 9 in one for the Measurements carried out operator arranged suitable height. One measuring beam 8 runs to the side of the vehicle. rronau parallel to its longitudinal axis and carries on its one ■; nd a light source .1Q. For this light source it is important that it can emit a tightly closed beam of light so that it can hit one of the rulers of the am Ileßbalken operator standing safely determined can be. A laser light source of the type He-Ne (helium-neon) fulfills these conditions.

In front of the light source 10 is a modulation unit 11, from which the further light beam with such a frequency is modulated so that the light reflected by this at a point of incidence appears flickering to the observer. One suitable frequency can be between 3 and 1.3 Hz. For the . Modulation unit 11, several embodiments are possible, which are described in more detail below.

On the measuring beam 8 there are in the tion unit 11, two beam units 12 modulated the light beam .and 13, .through which the light emanating from the laser

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lig is deflected to the measuring beam 8. The deflection unit 12 can are displaced along the measuring beam 8 and the deflection unit 13 is on the outer surface opposite the light source 10 = Ren end of the measuring bar 8 arranged at the point where deifir Same the measuring beam 9 goes out at right angles. As will be described in detail below, the deflector operates 12 with the modulation unit 11 together so that they partly emits a deflected modulated light beam and partly a straight forward light beam whose frequency is in phase opposition to the deflected light beam.

The deflection unit 13 reflects along the measuring beam 8 incoming light beam at right angles along the measuring beam 9, from which it is guided by a further deflection unit 14, which can be displaced on the same, to the same point of impact on the ruler 2 is deflected out, at which the deflection unit 12 from. deflected light beam strikes. Is the ruler 2 for example as a result of a deformation of the vehicle carrying it, however, not exactly at the intended intersection of the two deflected light beams and strike them with it on the ruler 2 also not at the same point of impact then the operator sees a flickering light at the point of impact. You must therefore the vehicle like that Align for a long time until the light from a common on the ruler 2 At the meeting point as constant light is reflected +: is.

The measuring device shown in FIG. 2, corresponding to the second exemplary embodiment, has only one along one side of the motor vehicle 1 to be measured running measuring balls 15 at one end of which a light source 16 and a modulation unit 17 are arranged in a stationary manner in front of it.

There are also two deflection units 18 on the measuring beam 15 and 19 displaceably arranged, which over the modulation? - unit 17 along the measuring beam 15 incoming light beam in

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a horizontal plane in mutually different directions deflect so that the ruler 2 is illuminated from two different directions. The position of the point of impact is here in a coordinate system assigned to the measuring beam 15 unambiguously by the position and the mutual spacing of the two deflection units 18 and 19 on the measuring beam 15 as well as through determines the two angles by which the light beams are deflected at the two deflection units with respect to the measuring beam 15 will. In Fig. 2, the two deflected light rays'

10 'len in a horizontal plane in which the point of impact is also located on the ruler 2; but it is just as possible to approach rulers suspended from the measuring points of the vehicle do without and deflect the light beams upwards by means of the deflection unit so that they directly hit the various S hit the pouring points. This is especially true in such cases expedient where the positions and deflections of the two deflection units are fed to a central processing unit, which is based on c ^ calculates the vehicle-related data and the same for example on an easy-to-read display board.

In the execution example shown in Fig. 3 modulates two beams of light. In front of the light source 23 embodied as a laser, one is rotating by a drive motor 25 Drivable disc 24 arranged, which are distributed in the circumferential direction similar sections 26 and 27 with light polarizing material, hereinafter called polaroids, is coated, which are aligned at right angles to each other are. These polaroids are struck along a concentric point by the light beam from the light source 23 at one point Ring of the disc 24 arranged so that it is in each of the successive Sections 26 and 27 of the ring alternately assume different positions. Are on the assigned measuring bar in the direction of the light beam emanating from the light source 23 successively two deflection units 28, 29 and 30, 31-provided with mirrors, which are analogous to the reflection surfaces

Γ / 5 of a pentagon prism are arranged. The deflection unit 2 · 8,

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has the light beam in arriving from the light source 23 deflect a right angle and for this purpose has two mirrors 28 enclosing an angle α of 45 ° in their position and 29 on. The deflection unit 30, 31 has to reflect back the light beam arriving from the light source 23 at an acute angle, so that it meets the other, perpendicularly deflected light beam at a certain measuring point can. In the illustrated Ausführungsbexspiel this acute angle is 45 °, while that between 'the two mirrors 30 and 31 included angles -Θ- then have a value of 67.5 °. When the two mirrors are 30 and 31 in this deflection unit are otherwise arranged analogously to the reflection surfaces of a pentagon prism, rotation dos remains the carriage carrying the deflection unit on the measuring beam without

Influence on the deflection angle. ''.

When the mirror 28 of the deflection unit 28, 29 polarizes and is coated, for example, with a dichroic crystal layer, the light polarized in one direction reflects, while it transmits light polarized in the other direction, the radiation is reflected by the mirror, if: the polaroids deflecting in one direction of the rotating disk 24 in the one emanating from the light source 23 Light beam are located, while they let the light beam through after the further deflection unit 30, 31 when the in the other direction deflecting polaroids of the rotating: disk 24 are located in the said light beam.

In the second exemplary embodiment, shown in FIG. 4, of an arrangement for modulating the light beam, the light sources are 23 ,. the one emanating from this along a measuring beam. 30. Light beam and the two deflection units 28, 29 and 30, 31 in in the same way as in the embodiment shown in FIG educated. Instead of a rotating disk that can be driven, there is a pockcil cell in the light beam of the light source 23

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■ 36 arranged by an alternating voltage with a Rechtockcharakte'ristik is excited.

In the further exemplary embodiment of an arrangement for modulating the light beam shown in FIG. 5, the light source 23 designed as a laser likewise emits a light beam along a measuring beam. This light beam hits a first deflection unit with mirrors 32 and 33 which are arranged in correspondence with the reflection surfaces of a pentagon prism and mutually enclose such an acute angle that the incoming light beam is deflected at an obtuse angle. If the angle between the deflected light beam and the direction of the incoming light beam is to be 45 °, this acute angle must have a value of 22.5 °. A second deflection unit 34, 35 through which a light beam arriving along the measuring bar is arranged in one ^! is deflected at right angles. The mirror 32 of the aforementioned deflection unit 32, 33 which is hit first by the light beam emanating from the light source 23 is provided with a floating crystal layer which has transparent electrodes on both sides. If a voltage above a certain voltage value is applied to this layer via the electrodes, the crystals have a reflective effect. Without a voltage application or with an applied voltage whose value is less than the aforementioned specific value, the crystals transmit the incident light beam. The light modulation is achieved in that a square-wave voltage is applied to the layer via the electrodes, which alternates between a voltage which effects the reflection and a voltage which effects the permeability of the crystals.

Various modifications are possible within the scope of the invention. For example, the rotating shown in FIG Disk 24 by a reciprocating effective arrangement. · Young be replaced, .by which Polaroids with alternately

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alternating deflecting alignment, into which the light beam e ⁴ n>'C - are brought. Instead of interacting with a laser. · ■ ..-! Rest units 12, 14, 18 and 19 could also each have an eiyeno light source and the same directly module-limited>; Units may be provided.

Under a workshop measuring device according to the invention ν, -ir ^;.; * .; ο another such described measuring device understood, which, in contrast to geodetic measuring devices, is used for re-measuring ;; r; J. '. ■ ·;: -: components of mechanical engineering and construction, niicli ^τ · ν. it outside. a workshop should be used.

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Claims (6)

■ ^ N ** WOi • "« * * β Ail -Ji ι. ...; ϋ PATENT Attorney DIPL.-ING. H. STROHSCHÄNK 8000 MÜNCHEN 60 · MUSÄUSSTRASSE 5 · TELEPHONE (0 89) 881608 April 23, 1981-Fri (5) 190J-1603P Patent claims 1 ν workshop measuring device to check the dimensional accuracy and / or for measuring the dimensions of large, with control points, such as screw heads and rulers suspended from them or the like., provided objects, e.g. vehicle bodies and the like, that at least " a measuring beam arranged along the object with at least two displaceable along the measuring beam and in its each setting has displayable transmission units, each of which has a narrow light beam in one opposite the measuring beam an angle enclosing direction aur, -sendbar is, . characterized, that the light beams from at least two on the measuring balcony (8 or 9, 15) occupying different positions transmission devices (12, 14 or 18, 19) in different phase positions are modulated with a modulation frequency that corresponds to the a point of impact located e.g. on a ruler (2) Make light of such a light beam appear flickering to an observing eye, but that on a e.g. visible light located on a ruler (2) make appear constant if, on the same more than one such a ray of light hits. 2. Measuring device according to claim 1, characterized in that in a known per se, at one end of a measuring beam (3, or 15) arranged and e.g. designed as a laser common light source (10 or 16) for all light beams two of deflection units (18, 19 or -12, 14) displaceable along the measuring beam (15) or along two measuring limbs (8, 9). BATH ORIGINAL • · a
* a a * O i lOZOÜ - 2 - Light beams are directed at a point of impact (ruler 2) and the deflection device (18 or 12) first hit by the light beam from the light source (16 or 10) has a mirror (28 or 32) hit first by the incoming light beam, ^r > der alternately reflects and transmits the incoming light beam. 3. Measuring device according to claim 2, characterized in that the light beam emanating from the light source (23) passes through a polaroid element (24 to 27) arranged in front of the light source (23) 1G or 36) with changing polarization alternately in two is polarized crossing directions and the mirror (23) consists of a polarized mirror. 4. Heßgerät according to claim 3, characterized in that the Polaroid element (24 to 27) a rotatably drivable disc 1 :: (24) with a concentric. Has ring of polaroids that . in the circumferential direction alternately in different directions are aligned, and that the disc (24) penetrates at one point of the polaroid ring by the optical axis of the light beam is. 5. Measuring device according to claim 3, characterized in that the Polaroid element than arranged on the optical axis of the light beam and connected to an alternating voltage via its electrodes Pockel cell (36) is formed. 6. · Measuring device according to claim 2, characterized in that the Mirror (32) with its electrodes at an alternating voltage applied floating crystal layer and this voltage between a value where the mirror is transparent and a value where the mirror reflects changes. BATH